A detailed study will be made of the lipid composition (including individual fatty acids) and metabolism of lipids of human testes obtained from patients with prostatic carcinoma, and with other problems which necessitate biopsy or other surgical removal of testicular tissue. Quantitative analysis of amounts of various lipid classes and of individual fatty acids will be done using modern methods of analysis, including thin-layer, column, and gas chromatography. Chemical identification of compounds isolated by gas chromatography will be done. The biosynthesis of fatty acids will be studied in tissue homogenates incubated with C14 labeled acetate, glucose, or citrate. Interconversion of fatty acids in tissue homogenates will be studied by use of labeled long chain saturated and unsaturated fatty acids. Radioactivity of individual fatty acids will be done by gas-liquid radiochromatography. Chemical degradation of labeled pure compounds will be used to ascertain the mode of biosynthesis. Oxidation of various labeled long chain saturated and unsaturated fatty acids will also be determined in homogenates of testicular tissue when possible. Findings of lipid composition and metabolism will be supplemented with a histological study of the tissue in order to study the role of the lipids in the physiological functioning of this organ. Studies of this type will also be done on human sperm obtained from "infertile subjects" and "fertile" subjects.